Adding selector to navigationbar button programmatically

I use to do that like this and works fine

    presetButton = [[UIButton alloc] initWithFrame:framePresetButton];
    UIImage *presetBtnBG = [[[UIImage imageNamed:@"segment_tools.png"] stretchableImageWithLeftCapWidth:12.0 topCapHeight:0.0] retain];


    [presetButton setImage:presetBtnBG forState:UIControlStateNormal];

    presetButtonItem = [[UIBarButtonItem alloc] initWithCustomView:presetButton];
    [presetButton addTarget:self action:@selector(loadPreset) forControlEvents:UIControlEventTouchUpInside];

    self.navigationItem.rightBarButtonItem = presetButtonItem;

So you say self.navigationController.navigationItem.rightBarButtonItem is nil, but rightBarButtonItem is hooked up in IB.

There are two reasons why this could be:

1. You haven't loaded your nib yet. (From what little I know of UIViewController, this seems unlikely.)
2. navigationItem, navigationController, or self is nil.

Remember that property access expressions are really message expressions. If, say, self.navigationController is nil, then sending it the navigationItem message will return nil. If, one way or the other, self.navigationController.navigationItem is nil, then asking it for its rightBarButtonItem will return nil.

Check every one of those sub-expressions—self, self.navigationController, and self.navigationController.navigationItem—and see which one is nil. Then, fix that one.

You should set also a target which will receive an action (I think you'll use 'self'):

[self.navigationController.navigationItem.rightBarButtonItem setAction:@selector(showWithLabel)];
[self.navigationController.navigationItem.rightBarButtonItem setTarget:self];

Just try to create rightBarButtonItem programmatically in viewDidLoad method:

UIBarButtonItem *rightBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemEdit target:self action:@selector(editEventQuestion)]; 
self.navigationItem.rightBarButtonItem = rightBarButtonItem;
[rightBarButtonItem release];

Try adding a colon after your selector name, like this:

[self.navigationController.navigationItem.rightBarButtonItem setAction:@selector(showWithLabel:)];